Method for the production of N-cyclic and N,N'-dicyclic ureas and their use as chemical solvents

Abstract

A process for the dissolution of chemical compounds by use of ureas in which at least one of the urea's two nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom as a chemical solvent, and a method of producing tri- or tetraalkylated ureas or bis ureas wherein at least one of the urea's nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom by means of dialkylating the --NH 2 group of a urea with an alkene or alkene arylene alkene dihalogenide, disulphonate or dihydrogen sulphonate in the presence of a solid base and a phase-transfer catalyst.

What we claim is: 
     
       1. A process for the dissolution of a chemical compound by a chemical solvent comprising dissolving a chemical compound in at least one urea of the formula ##STR5## in which R 1  and R 2  independently of one another denote a straight-chain, branched or cyclic alkyl group having 1 to 22 C atoms, which is unsubstituted or substituted by fluorine atoms; nitro groups; alkenyl- or alkylidene groups having 2 to 6 C atoms; phenyl groups which are unsubstituted or substituted by fluorine atoms, nitro groups, alkyl groups having 1 to 5 C atoms, alkoxy groups having 1 to 5 C atoms or phenoxy groups; benzyl or phenylethyl groups which are unsubstituted or substituted by fluorine atoms, nitro groups, alkyl groups having 1 to 5 C atoms, alkoxy groups having 1 to 5 C atoms or phenoxy groups; alkoxy groups having 1 to 5 C atoms, phenoxy groups which are unsubstituted or substituted by fluorine atoms, nitro groups, alkyl groups having 1 to 5 C atoms, alkoxy groups having 1 to 5 C atoms or phenoxy groups; or, together with the nitrogen atom, a five or six-member non-aromatic ring which can be broken by an oxygen or sulphur atom; Y represents a methylene group, an oxygen or sulphur atom, n and m represent independently of one another the numbers 1 to 3, whereby n plus m represent the numbers 3 or 4. 
     
     
       2. The process as claimed in claim 1, wherein R 1  and R 2  representing independently of one another straight-chain unsubstituted alkyl groups or represent together with the nitrogen atom an unsubstituted 5 or 6-member non-aromatic ring which can be broken by an oxygen atom. 
     
     
       3. The process as claimed in claim 1, comprising Y representing a methylene group or an oxygen atom; n and m representing independently of one another the numbers 1 or 2, and n plus m representing the numbers 3 or 4. 
     
     
       4. The process as claimed in claim 1, comprising R 1  und R 2  representing alkyl groups with 1 to 6 C atoms or, together with the nitrogen atom, a 5 or 6-member non-aromatic ring which can be broken by an oxygen atom.